Whenever hydrocarbons are to be produced offshore, production and injection subsea wells should be drilled, as well as subsea equipment should be installed, such as Wet Christmas Tree (WCT), manifolds, PLET (pipe line end termination), PLEM (pipe line end manifold), Pumping Adapter Bases (PuAB), Production Adapter Bases (PrAB), flow lines and risers between the wellhead and the production unit. Such production unit can be placed on a ship, on a platform or even on shore.
In spite of the fact that many of such equipment are installed separately in the subsea in independent operations, they should operate in an interconnected way, allowing the flow of fluids such as hydrocarbons, gas or water and sometimes control commands and electrical measurement signals between same. Nowadays, such interconnections between subsea equipment are implemented following the installation of the subsea equipment, with the aid of flow lines and control umbilicals or jumpers, the ends of which are fitted with mechanical or hydraulic connectors for effecting the fixing or locking and sealing between such lines and parts (mandrels) of the equipment which have been previously installed in the subsea.
Usually the interconnection of previously installed equipment in the subsea using flow lines can be performed with the aid of two kinds of flow lines: flexible lines and rigid or stiff lines.
Flexible lines are endowed with certain mechanical features (flexibility), and do not require measurements (metrology) between the points to be interconnected, since their flexibility makes possible to adapt their geometry to the existing conditions of angles and distance or space between the points to be interconnected.
Rigid lines (made up of short spans of rigid pipes and accessories such as bends) bear certain mechanical features (rigidity) that require subsea assessment of angles and distances between the points to be interconnected, for further onshore manufacture of the flow line span to be installed in the sea bottom.
However, interconnecting lines the ends of which are fitted with connectors or jumpers, besides their high cost, require the use of sophisticated ships, this leading to high installation costs.
Among the subsea equipment to be installed and that should bear such flow interconnections are the Pumping Adapter Bases or PuAB designed to support and accommodate pumping units. Such pumping units can use several types of pumps, among which, the Electrical Submersible Pumps (ESP's), as well as multiphase pumps. The geometry of ESP pumps makes them tall and thin, designed to be installed within wells while multiphase pumps have a compact geometry, designed to be installed in the marine soil (out of the well).
From Brazilian Application PI 0301255-7 of the Applicant and herein completely incorporated as reference, it is known that it is possible to utilize a pumping module directly connected to a subsea equipment such as a wellhead and WCT unit. Such pumping module is made up of a closed tubular body and a hydraulic connector, where such connector is coupled to the flow mandrel of the subsea equipment previously installed in the sea bottom.
In spite of the fact that the subject matter of said Brazilian application enables a direct connection between subsea equipment, a drawback of the technology presented therein is the need to make modifications by altering the normal manufacture standard through increased weight, dimensions and cost of the WCT unit. Besides, the proposed layout does not facilitate the installation of long ESP's units having tens of meters.
A further drawback of the described system is that it is hard to apply same to already existing wells, since some parts of the wellhead/WCT unit should be exchanged, that is, requires the well to be re-completed and the production string withdrawn.
U.S. Pat. No. 4,900,433 and U.S. Pat. No. 6,036,749 cite that a pump similar to an ESP is installed in the interior of a dummy well, such well being built aiming at accommodating the separation and pumping unit, as well as driving the flow of oil from the inlet of such well up to the pump suction installed in the interior of same.
Also, from U.S. Pat. Nos. 6,419,458 and 6,688,392 it is known that it is possible to install a subsea pile-sump pumping arrangement similar to an ESP, hydraulically connected to a dummy well.
Brazilian Application PI 0400926-6 (and corresponding U.S. application Ser. No. 10/982,848) of the Applicant and equally herein completely incorporated as reference teaches that it is possible to install a pumping module housed within a cased borehole (hollow pile) in the marine soil and coupled to a PuAB. Such borehole is located apart from the wellhead, requiring the installation of short flow lines (tens of meters) and lines (umbilicals) for control and data acquisition. Those connecting jumpers, although short, having a few tens of meters, require high costs in material and ships to be installed.
Brazilian Application PI 0404603-0 of the Applicant and herein also completely incorporated as reference teaches the installation of a pumping module inserted within a cased borehole (hollow pile), or in the water-capturing well itself in water-capturing and injection systems of subterranean aquifers.
Thus, in spite of the previous developments, there is still in the art the need of a system and method enabling the installation and direct connection with hydrocarbon flow and/or control interconnection (dispensing with flow lines fitted with connectors) of any subsea equipment, for example, a PUAB described in Brazilian PI 0400926-6 to at least another contiguous, previously installed subsea equipment, such system and method being described and claimed in the present application.